The huge growth in mobile success in 2012 came not from innovative, brand-new strategies on smartphone platforms, but rather Facebook’s decision to update existing products and improve the user experience. In the Q4 2012 earnings call and at TechCrunch Disrupt in September, Zuckerberg said a faster app alone did wonders from the company’s traffic:

“Often, doing a good job is focusing on basic issues like performance and stability,” he said Wednesday.

But during 2013, Facebook and everyone else will need to think about what exactly makes an app shine on mobile, and then go build it themselves. Eventually, just being faster or bigger might not be enough to maintain growth.

Facebook needs to build the Instagrams, Snapchats, or Vines of tomorrow that actually engage mobile users in a new way. And clearly, Zuckerberg recognizes this:

“Now we’re there. We moved fast and ship new versions of our apps on regular monthly schedules,” he said. “Now the next thing we’re going to do is build really good mobile-first expierences.”

But when he says mobile-first, does he mean an actual mobile device? Nope, don’t hold your breath. There’s no Facebook phone on the horizon, Zuckerberg said.

“The big theme that we’re going to push on is mobile. People keep asking if we’re going to build a phone. And we’re not going to build a phone. Because it doesn’t make sense for us,” he said. “We have a billion people using our product and we have to make Facebook really good across all the devices they’re using.”

Instead, Facebook needs to be the company that solves the mobile ad dilemma, or at least, among the fast followers. The torch has been passed to a new generation of computing at Facebook, and it doesn’t involve the traditional PC.